1. Field of the Invention
The present invention relates to a signal detecting method and device, and more particularly, to a detecting method and device for suppressing the interference of low-frequency noise.
2. Description of the Prior Art
When a signal such as the one shown in FIG. 1C is received under the interference of low-frequency noise, this signal may become distorted. The signal is, for example, used as a driving signal for a capacitive touch sensor. The capacitive touch sensor includes a plurality of detecting electrodes. When the driving signal is provided to one or more of the detecting electrodes, self-capacitive coupling by the detecting electrodes themselves, or mutual-capacitive coupling between the electrodes may be generated. When an external conductive object approaches or touches the capacitive touch screen, changes in capacitive coupling will occur in some of the detecting electrodes. Through this change in capacitive coupling, the location of the external conductive object can be determined.
However, low-frequency noise may easily inject into the capacitive touch sensor through the external conductive object, it may distort the change in capacitive coupling described before, thereby creating errors in the determination of the location of the external conductive object.
From the above it is clear that prior art still has shortcomings. In order to solve these problems, efforts have long been made in vain, while ordinary products and methods offering no appropriate structures and methods. Thus, there is a need in the industry for a novel technique that solves these problems.